footwork
I don't expect composers to spend every waking moment studying the harp. But for heaven's sake, I have been given a trio for a composers' workshop that has 8 pedal changes in 4 beats, most of which have to be done with the same foot. It isn't a brief moment of forgetfulness, practically every bloody bar is like this.
Look, composers. This is how the pedals work. The left foot does D, C and B. The right foot does E, F, G and A. It is possible to play the E and F pedals with the left foot, but it is much harder to play any of the left foot pedals with the right, because the harp is on the right shoulder, and it makes it very difficult to stretch the right leg over to the left. E + G, F or A together are the best pedal-that-should-be-a-right-footer-but-can-be-done-with-the-left. F + any of the others is possible but difficult. It is not possible to move more than two pedals together with the same foot, unless your name is Park Stickney, or you wear size 12 shoes.
It's fair enough to say, if something is possible, its difficulty is the player's problem. But even if your harpist moves all her pedals perfectly, the other effect of a lot of pedals is it necessarily leads to a lot of damping. If you play a 4th octave F natural, followed quickly by a higher F sharp, and it isn't possible to play the F sharp as a G flat because you have written in a G natural somewhere as well, the harpist must damp the first F string to avoid hearing the pedal change.
If you want the sound cut off all the time, that's up to you, although Harrison Birtwistle's new solo work might convince you otherwise (TwTwTw will give the UK premiere at the Cheltenham Festival on July 7th).
While I remember, I might as well also point out that extreme registers together - the LH playing the deepest bass while the RH tinkles feebly right up at the top, almost always sound naff as well.
So there.